The Prime Minister is moving closer to an admission that civilians died during a New Zealand SAS raid in Afghanistan.

"The allegations have created I suppose some uncertainty about civilians," Mr English says.

That's a big shift from previous denials over civilian deaths.

It comes after then Defence Minister Wayne Mapp told Newshub of his remorse around the operation, and admitted he called the raid "our biggest and most disastrous operation - a fiasco".

"I'm sure everyone was remorseful about that," Mr Mapp says.

"At the time of the attack they thought they were getting attacked by insurgents."

That's not enough to shift the government's position on launching an inquiry.

"He doesn't have any new information than what has been available to the defence forces or the government," Mr English says.

The Labour Party says this isn't good enough.

"I think what people need is the reassurance that there's been an independent inquiry and that's all we're asking for," Labour Deputy Leader Jacinda Ardern says.

Deputy Prime Minister Paula Bennett says it all has to wait - the Prime Minister needs to be briefed by his Defence Minister and the Chief of Defence - both of whom have been on a secret mission to Iraq.

But it's clear the Government will face questions about this for a long time yet.